1. Field of the Invention
The present invention relates to an image forming apparatus.
2. Description of the Related Art
Conventional image forming apparatus such as a dot printer is provided with a paper width sensor. Prior to printing on print paper, a print head is caused to run in a direction substantially perpendicular to a direction of travel of the print paper, thereby detecting the width of the print paper. Then, based on the detected width of the print paper, control is performed to identify the location on the print paper on which printing should be made, thereby preventing fault printing outside of the print paper area as well as transporting the print paper to an appropriate position.
With such an image forming apparatus, the detection of paper width is performed for each page of print paper fed from a paper cassette.
However, detecting the paper width of each page prior to printing requires a longer time for printing each page, resulting in a decreased throughout of the image forming apparatus.
With the conventional apparatus, the width of print paper is detected even when the print paper is fed from the paper cassette. Because all pages of the print paper held in the same paper cassette have the same width, when a plurality of pages are to be printed, it is only necessary to detect the width of the first page.